Vacuum matrix control



p 26 1939. H. A. w. WOOD ET AL 2,113 990 VACUUM MATRIX CONTROL Filed Sept. 16, 1957 3 Sheets-Sheet 1 j jwdem? p H. A. w. WOOD El AL VACUUM MATRIX CONTROL 3 Sheets-Sheet 2 Filed Sept. 16, 1937 mun...

' P 26, 1939- H. A. w. wooD ET AL- 3,990

' VACUUM MATRIX CONTROL Filed Sept. 16, 1957 5 Sheets-Sheet 3 Jrw/ezrg wand. 712:? 7602 Cara ,3,

Patented Sept. 26, 1939 UNITED STATES VACUUM MATRIX CONTROL Henry A. Wise Wood, New York, and Cortland J. Strang, Mount Vernon, N. Y., assignors to Wood Newspaper Machinery Corporation,

New York, N. Y., a corporation of Virginia Application September 16, 1937, Serial No. 164,132

1 Claim.

This invention relates to a stereotype printing plate casting machine and can be applied to the usual machine for this purpose but is designed in the present instance particularly for use in conjunction with the stereotype plate casting machine described in Patent No. 1,848,592.

The principal object of this invention is to provide means acting all over the rear surface of the matrix to hold it tightly and smoothly against the surface of the casting box at all times during the period of pouring and cooling of the plate.

More specifically the means for accomplishing this result is pneumatic. This is of high importance for, if the matrix does not closely fit the surface of the casting box, the resulting plate may be uneven in thickness and the outside surface of the plate will not be concentric with the inside surface. These sinks in the surface of the plate will, in use, show up by defective printing.

Another important feature of this invention is the means for automatically shutting off the vacuum used in holding the matrix before the mold is opened and throwing the vacuum on again as the mold is closed.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in which- Fig. 1 is a sectional View of the top of a casting box and associated parts arranged on a vertical axis for casting in accordance with this invention, showing most of the parts in plan;

Fig. 2 is a side View of the same, looking in the direction of the arrow 2 in Fig. 1 and partially broken away;

Fig. 3 is a longitudinal radial sectional view on the line 3-3 of Fig. 1 showing the matrix in place;

Fig. 4 is a horizontal sectional View through the casting box on enlarged scale, and

Fig, 5 is a view showing the relative arrangement of the vacuum pump, solenoid valve, vacuum relief valve and wiring diagram.

The principal idea of this invention is to hold the matrix by suction against the casting box during the time of pouring and cooling. During part of the cycle of producing the plate the suction is relieved to facilitate manipulating of the matrix, as for example, inserting, adjusting, or

vention can be applied to a casting box in any position.

In the surface of the casting box Ill on which the matrix 12 is held are. drilled a plurality of radial holes I 3. These all communicate with vertical longitudinal holes or passages H passing from the bottom upwards to the top of the matrix and beyond it, preferably. These holes H are located in the body of the box between the water chamber 20 and the inner finished wall 2| which, in this case, is semi-circular and receives the matrix 12. The holes I I are drilled so deep that they extend beyond the upper end of the matrix I2 when this is properly placed in the box.

The holes II penetrate the wall from the bottom and are always intersected by the holes l3. The lower end of the box is finished. The holes ll extend into the manifold I4, which is bolted against the lower end of the box, providing an air-tight enclosure around all these holes H. A screw-threaded opening l5 in this manifold connects it to an air-tight flexible tube It. The other end of the tube It connects with a spring opened vacuum relief valve H which limits the minimum pressure in the system and allows the air from the perforated area to the exhaust means only so far as its housing forms a part of the connecting piping. As shown in Fig. 5, this valve-forms the connection between a solenoid operated valve I8 and a vacuum pump H9 or other source of vacuum. The vacuum pump I9 runs continuously while the machine is in use and the valve I8 is ordinarily closed.

The vacuum pump I 9 ordinarily, through the relief valve ll, will suck the air from pipes 22, 23 and the flexible pipe Hi. It will also suck the air from the manifold M and will create a suction in the holes H and I3 over the entire surface of the matrix.

If the matrix is placed against the inside of the box, there is a sucking action of the multiple of holes l3 and the matrix will naturally be sucked against the same over its entire surface by the sucking action against the multiple of holes 13. This sucking action will continue until the solenoid 25 of the vacuum valve I8 is energized. This opens the valve !8 and admits external air freely into the system through a pipe 24 and releases the vacuum, thus enabling the matrix to be stripped from the plate, put in, adjusted or taken out, as desired. This vacuum arrangement is used with the means normally employed for holding the matrix, as shown in Patent No. 1,848,592. This relief valve ll may be adjusted for the proper amount of vacuum in the box.

The valve I8 is operated by the solenoid 25 which is controlled through the wires shown, or otherwise, by a limit switch 26. This switch is normally closed when the machine is idle, as shown in Fig. 5 so that the valve I8 will be open. It is operated by a crank and roller 2'! on the side of the switch. This roller is operated by a face cam 28 which is fastened to the end of a cam shaft 29 which is part of the casting machine. The cam is so made and timed that it will act to deenergize the solenoid 25 and close the valve 18 just prior to and during the time the plate is being poured and cooled. This, of course, keeps the valve l8 closed and keeps the vacuum on the box during this period. At all other points of the cycle the switch will be closed, the valve l8 will be opened and there will be no vacuum in the box. The casting box is shown as water cooled having a water chamber 20.

It is apparent, therefore, that when used with an automatic stereotyping machine, such as in the above mentioned patent, means is provided for automatically creating a vacuum for holding the matrix firmly against the surface of the casting box while the casting is being made and cooled and then breaking that vacuum automatically so that the matrix may be stripped easily from the newly cast plate, and this action is repetitive.

Having thus described our invention and the advantages thereof, we do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claim, but what we claim is:

Thecombination with a casting box shaft, of a perforated area in said casting box, means for exhausting the air behind said perforated area, an air admission valve connected with the means for exhausting the air behind the perforated area, electrically actuated means for opening said valve to admit outside air to the perforated area, a limit switch connected with said means and a source of electric power in series, and means operated by said shaft for controlling said electrically actuated means by said limit switch in such timing that the perforated surface will be in exhausted condition at regular intervals during the successive rotations of said shaft.

HENRY A. WISE WOOD. CORTLAND J. STRANG. 

